Power transmission



Jan. s, 1957 A. KEEL 2,776,627

POWER TRANSMISSION Filed July 10, 1952 INVENTOR.

ADOLF KEEL ATTORNEY .is.-connected to operate certain types of loads.

United States Patent POWER TRANSMISSION Adolf Keel, Highland Park, Mich, assignor to Vickers Incorporated, Detroit, Mich Michigan Application July 10, 1952, Serial No. 298,079

4 Claims. (Cl. 103-162) This invention relates to power transmissions, and is particularly applicable to those of the type comprising two or more fluid pressure energy translating devices, one of which may function as a pump and another as a fluid motor. i

The invention is more particularly concerned with a fluid pump or motor construction of the type having a rotary cylinder barrel abutting a stationary valve plate and provided with axial cylinders and pistons reciprocal therein which abut against a thrust plate, the axis of which is inclined to the axis of rotation of the cylinder barrel. It is particularly concerned with that class of devices wherein the pistons abut directly against the inclined thrust plate without the use of articulated connectv ing rods so that the driving torque is transmitted to the pistons acting as cantilevers by reason of that component of piston thrust against the inclined thrust plate which is normal to the shaft axis.

When a unit of this type is operating under pressure, certain related areas are so proportioned that the cylinder barrel is positively biased toward the valve plate by that pressure in a manner well known in the art. For purposes of starting, however, it is necessary that the barrel be mechanically biased against the valve plate. Further, it is necessary that the pistons be biased outwardly toward the thrust plate to provide proper operation of the device.

'In such devices, the normal thrust component or side thrust on the piston not only creates the driving torque but also results in a substantial lateralforce on the cylinder barrel tending to displace it from its normal position. In counteracting this lateral force it is important that the cylinder barrel be maintained flatly against the valve plate or it will frequently lift off completely due to fluid flow conditions let up when it starts to lift ofi slightly. This of course renders the Whole device inoperative and may be very hazardous where the device The axial a corporation of ice . an improved cantilever piston type pump or motor of rugged, low cost construction.

More specifically, it is an object to provide such a device having improved means for biasing the cylinder barrel against the valve plate and the pistons outwardly against the thrust plate.

A further object is to provide such means which are particularly well suited for use with a cantilever piston pump in which the cylinder barrel is drive shaft supported.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of the present invention is clearly shown.

In the drawing:

Figure 1 is a longitudinal transverse section of a fluid pressure energy translating device incorporating a preferred form of the present invention.

Figure 2 is a partial section taken on line 22 of Figure l.

The embodiment of the invention selected for illustration comprises pump 10 of the cantilever piston type. The housing 12 of pump 10 comprises two parts 14 and 16 secured together by bolts 18. An 0 ring seal 20 insures a fluid tight juncture of the two parts and the dowel pin 22 maintains proper angular alignment between them. Body 12 includes a pilot portion 24 and a mounting flange 26 having mounting holes 28 therein.

.A bore 30 in housing 12 provides a chamber 32 having a cylinder barrel 34 positioned therein. Cylinder barrel 34 is provided with a plurality of bores 36, each having a piston 33 axially slidable therein and a cylinder port 37. Pistons 38 have spherical ends 40 on which are swaged the socketed shoes 42. The cylinder barrel 34 is positioned axially between a valve plate 44 and an inclined thrust plate 46. Valve plate 44 may be the type described in the patent to Harry F. Vickers et al., 2,313,407, and serves in a well known manner to provide properly phased fluid connection between ports 37 of bores 36 and the external inlet and outlet connection ports of the device, one of which is indicated at 48. Thrust plate 46 is secured to the housing 12 by a number of screws 50 sealed against leakage from chamber 32 by 0 rings 52.

- contacts the spherical outer surface 66 of a collar 68 position of the point of application of the cylinder barrel 7 supporting force may be so selected as tominirnize tilting'forces on the barrel as hereinafter described.

In priorart devices of this class, support for the i cylinder barrel against lateral displacement has been provided by two general schemes. vides a radial bearing encircling the cylinder barrel directly interposed between the cylinder barrel and the housing. The second scheme has been to. support the cylinder barrel directly on the shaft at the driving connection therewith, and transmit the lateral thrust thereon'to the r housing through the shaft and shaft support.

The first of these prowhich is provided with a female spline to engage a male spline on the cylinder barrel at 70. A plurality of springs 72in recesses 74 in cylinder barrel 34 act through collar 68, sleeve 60, and cage 56 to bias the shoes 42 into engagement with the face 47 of thrust plate 46. The reaction force of springs 72 biases face 35 of the cylinder barrel 34 into engagement with face 45 of valve plate 44.

A drive shaft 76 is effective to transmit torque from a prime mover, not shown, to the cylinder barrel through a driving connection at 78. Further, it can be seen that the only radial support for cylinder barrel 34 is provided by the contact between the barrel and the shaft 76 at connection 78. Connection 78 is illustrated as a spline connection and preferably is of the universal type,

that is, it prevents relative radial movement at the point of connection between shaft 76 and barrel 34 but permits axial movement of the barrel and existence of angularity between the shaft and cylinder barrel axes. Thus juncture of the faces 35 and 45 locates cylinder barrel 34' as to axial position and determines the angular position of its axis,- and connection 78 locates the barrel radially.

Referring to Figure 2, it can be seen that the spline connection 70 between the collar 68 and cylinder barrel 34 is concentric with the spline connection 78'between barrel 34 and shaft 76. Spline connection-J" provides, in a short axial distance,- strong support for; collar 68 against cocking relative to cylinder barrel34';

Neglecting friction, torque applied to cylinder barrel;

34 by drive shaft 76 is resisted by a force exerted on -shoes 42 and hencepistons 38- by thrust plate 46'. The force oneach piston acts inadirectionnormal toface 47 of 1 thrust plate 46 and has an effective pointof application" by providing its radial support as close as-possible to a:

radial plane through the point ofintersection.offthedrive shaft axis and the plane which includes the centers ofthe spherical ends of the pistons. The plane containing the centers of'the piston ends isindicatedat 80'andfthe point-ofintersection with the. shaft axis at. 82;- It canv,

be seen that connection 781s axially, centered 'ab'outthe intersection 82thus minimizing, tipping forces. on the. barrel'34:

The axis 65 of the conical bore 64 intersects the axis, of 'shaft76 at the point 82"and point 82 is also thecenter of the spherical surface 66' of'collar 68 as indicated by the radius 67: The geometrical arrangementdescribed insures thatsleeve 6t) and collar 68' can rotate freely about their respective axeswhile at the same time full circle-contact ismaintained between spherical surface 66. and conical bore 64. Further, relative motion between cage 56=andshoes 42 is thus minimized. Springs 72; are effective to bias the cylinder barrel 34 against valve plate,

44 and. shoes 42" against thrust plate-46 without appre-- ciable flexure duringoperation of the unit. Long, trouble free life isthus assured.

A cylindrical extension 84 is provided, on theportion 14 of housing 12,1which protrudes from the face 86,

against which face the valve plate 44 rests. Extension 84 has a bearing bore 83 at its outward end and carries a shaft support bearing 90therein. A second shaft support bearing 92. and a shaft seal 94 are provided inthe shaft bore 96. Valve plate 44 and cylinder barrel 34 are.

provided with clearance bores 98 and 100', respectively;

through which extension 84 passes. Bearing 90 is thus; positionedin axial -proximity to the connection 78 and. thebending moment created by the radialload of barrel.

340m shaft 76 is minimized.

It will .thus.be seen that the present invention. provides a rugged, low cost, and compact cantilever piston" pump or motor having improvedl means for biasingthe cylinder barrel'against the valve plate. and the pistons-- outwardly toward the-thrust plate. Further, the inven-v tion providessuch means especially Well suited. for use. in a unit having a shaft supported cylinder barrel since.

the barrel support and the, piston biasing, mechanism may both be positioned at their optimum location .without interference.

and having a plurality of axial cylinder bores; pistons reciprocable in the bores each having a spherical'surface' at one end; an inclined thrust plate mounted in the housing in driving relation with the pistons; inlet and outlet ports alternately connectable through the valve plate to said cylinder bores by rotation of the cylinder barrel; means on the shaft for locating. the barrel as to lateral position; an axially slidable collar encircling the drive shaft and having a spherical'outer surface; a sleeve member having-a conical bore. contacting the. spherical outer surface of the collar, thecenter: of 'said spherical'outer surface being positioned at the intersection of the axis of the conical boreand-theaxis of thedriveeshaft, the intersection of said axes being coincident with the point on the shaft axis at whichathe shaft axis-pierces the plane containing the centers of said spherical surfaces at the ends of the pistons; a mechanical force transmitting connection between said sleeve and said pistons; and resilienti biasing means exerted betweenthe. cylinder barrel.- and' said collar whereby. the. cylinder: barrel is biased' against the valve plate and the,pistons are biasedtoward, the thrust plate.

2. A fluid pressure-energy, translating device comprising: a drive shaft;.a housing. having a stationary valveplate; a rotatable cylinder barrel in abutment with; the. valve plate and in driving relation with the drive shaft, and having a plurality of axial cylinder bores; pistons. reciprocable in the bores and having a spherical surface. at one end of each piston; an inclined thrust plate mounted. in the housing in driving relation with. the pistons; inletand'outlet ports alternately connectable through the valve plate to said cylinder. bores by. rotation of the cylinder barrel; means on the shaft for locating the barrel as-tolateral position, said means including in its axial extent the point on the shaft axis at which the shaft axis'pierces the planecontaining the center of said spherical surfaces at the ends of the pistons; an axially slidable collaremcircling the drive shaft and having a spherical outer surface; a sleeve member having a conical bore contacting the spherical outer surface of the collar, the center of said spherical outer surface beingpositioned at the inter-- sectionof the axis of the conical bore and the. axis of the' drive, shaft, the. intersection of said axes beingtcoincident. with the point on the shaft axis at which the shaft axis piercesthe plane containingthe centers of said spherical surfaceat the ends of the pistons; a mechanical force. transmitting connection between said sleeve andsaid pistons; and resilient biasing means exerted between the cylinderbarrel andsaid collar whereby the cylindenbarrel is biasedjagainst the valve plate and;the pistonsare biased towardthe thrust plate.

3, A fluidpressure energy translating device.compris-.- ing:. adrive shaft; a housing having a stationary valveplate;,a rotatable cylinder barrel in abutment with the valve plate and in driving relation with the drive'shaft and. having a plurality of axial cylinder bores; pistonsreciprocable in the bores and having-aspherical surface;

at one end of each'piston; an inclined thrustplate mounted.-.

in,thehousingindriving relation withthe pistonspinlet and. outlet ports alternately connectable through thevalve: plateto. said-cylinder bores by rotation of the-cylinder; barrel; means on the shaft for locatingthe barrel as.-to;

' lateralposition, said means including in its:axial.extent While the. form of embodiment of theinvention as herein disclosed constitutes a preferrediform, it is to-.be'

understood that otherforms mightbe adopted, all coming within the scope. of the claims which follow.

What is'claimed is as follows:

valve plate, andin driving relation with thedrive shaft,

the point on the shaft axis at which the shaft axis-pierces. the plane containing the center of said spherical surfaces. atthe endsof, the pistons; an axially slidable collar. en-- circling the driveshaft and having asphericalouter. sur-- face; .asleevemember having a central recess-contacting the spherical outer surface of .thecollar, the.;center.-ofisaid' sphericalouter surface being. positioned at the point on: the-shaft'axis at which theshaft axis piercestheplane containing the: centers of said spherical surface -at'thc' ends, of the pistons; a mechanical force transmittingzcomnection between said sleeve and said pistons; and resilient biasing means exerted between the cylinder barrel and said collar whereby the cylinder barrel is biased against the valve plate and the pistons are biased toward the thrust plate.

4. A fluid pressure energy translating device comprising: a drive shaft; a housing having a stationary valve plate; a rotatable cylinder barrel in abutment with the valve plate and in driving relation with the drive shaft, and having a plurality of axial cylinder bores; pistons reciprocable in the bores; an inclined thrust plate mounted in the housing in driving relation with the pistons; inlet and outlet ports alternately connectable through the valve plate to said cylinder bores by rotation of the cylinder barrel; means on the shaft for locating the barrel as to lateral position; an axially slidable collar encircling the drive shaft and having a spherical outer surface, said collar being so positioned that the center of said spherical surface lies on the drive shaft axis and approximately coincident with the axial center of said means on the shaft; a sleeve member having a central recess contacting the spherical outer surface of the collar; a mechanical force transmitting connection between said sleeve and said pistons; and resilient biasing means exerted between the cylinder barrel and said collar whereby the cylinder barrel is biased against the valve plate and the pistons are biased toward the thrust plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,539,616 Williams May 26, 1925 2,543,624 Gabriel Feb. 27, 1951 2,620,738 Huber Dec. 9, 1952 2,633,104 Lauck Mar. 31, 1953 2,642,810 Robinson June 23, 1953 

